1. Technical Field
The present invention relates to integrated circuit design and fabrication. More specifically, the present invention relates to methods and apparatuses for using aerial image sensitivity to model mask errors.
2. Related Art
Rapid advances in computing technology have made it possible to perform trillions of computational operations each second on data sets that are sometimes as large as trillions of bytes. These advances can be attributed to the dramatic improvements in semiconductor manufacturing technologies which have made it possible to integrate tens of millions of devices onto a single chip.
Conventional photolithography processes are close to reaching their physical limit in terms of the minimum feature size that can be printed with these technologies. Hence, the semiconductor industry is actively considering various next generation photolithography technologies which will enable feature sizes to be miniaturized even further. One of the more promising technologies is extreme ultraviolet lithography (EUV lithography).
As semiconductor manufacturing technologies continue to reduce feature sizes, process model accuracy and efficiency is becoming increasingly important. Inaccuracies in the process model negatively affect the efficacy of downstream applications. For example, inaccuracies in the photolithography process model can reduce the efficacy of optical proximity correction (OPC). If the process model is computationally inefficient, it can increase the time-to-market for an integrated circuit, which can cost millions of dollars in lost revenue. Hence, it is desirable to improve the accuracy and the efficiency of a process model.